In a variety of pursuits, there is frequently a need to secure a line or rope between one point and another remote or elevated point. For example, in the rescue field, so-called "high angle" rescue often necessitates placing a rope or line up to a point high off the ground, such as a building, a tower, a chair lift on a ski slope, or other structure. A rope is generally put in place by first throwing or propelling a weighted object, to which a light line is attached, over a weight-supporting part of the structure so that the object falls back to the ground with the light line still attached. The light line is then attached to the stronger rope and the rope is pulled up and over the structure, whereupon the rope is secured in a desired manner.
The method of throwing the weighted object to the desired point has obvious drawbacks and limitations, the principal ones being that most persons cannot throw an object to a very significant height above the ground, and most persons cannot always throw an object upward with the degree of accuracy required to place the object where it is needed.
Accordingly, slingshot-type devices have been developed for propelling an object over a greater distance and with greater accuracy than possible by throwing. Most of these, however, are hand-held devices in which a forked member is held in one hand and a sling carrying the object to be propelled is pulled back against the force of elastic bands or the like and then released. One disadvantage of such devices is that the biomechanics of pulling the sling back are poor, i.e., an average person cannot exert a great amount of force by pulling with one arm in the direction required by such devices. Thus, even though the elastic bands might be strong enough to potentially propel the object to a substantial height, the average person cannot utilize the full potential of the device because he or she cannot pull the sling back far enough. Another disadvantage of such devices is that they are awkward to use when propelling an object vertically upward, and therefore are not particularly accurate for such purpose.